1. Field of the Invention
The present invention relates to a driving method of an LCD device having a backlight module with dynamic backlight control unit, and more particularly for controlling backlight module of LCD which dynamically adjusts backlight brightness from grayscale level distribution of the display by frame data analysis. Due to dynamically adjusting backlight brightness, electric power consumption can be diminished and display quality can be enhanced.
2. Description of the Prior Art
Conventional backlight module of LCD is illustrated as FIG. 1. A backlight module 9 as shown on FIG. 1 includes a diffuser 91, a reflector 92 and a plurality of light source 93, wherein the reflector and plurality of light source are on the side of the diffuser and the plurality of light source is distributed between the reflector and diffuser regularly. Reflecting side 921 of the reflector comprises transverse concaves which have the plurality of light source on their focus and reflects light to the diffuser. Light from the plurality of light source can directly go through the diffuser and can be reflected by the reflector to the diffuser. Intensity or brightness of light source is controlled by a controller (not shown on FIG. 1). In general, the light source can be cold cathode fluorescent lamp (CCFL) as cylinders 93 on FIG. 1. The controller for CCFL is inverter controller (not shown on FIG. 1) which controls brightness of CCFL by pulse width modulation (PWM). As LCD developing, strip lamp 94 formed by light emitting diodes 941 (LEDs) in serial on strip board 942 can be the light source of LCD instead of CCFL. The PWM of strip lamp is controlled by LED driver controller (not shown on FIG. 1).
As increasing size of LCD, number and intensity of the light source (CCFL 93 or strip LED lamp 94) increase too. Electric power consumption increases also. In an exemplary LCD with 65-inch panel, electric power consumption for turning on the backlight module 9 is greater than 700 W as well as an operating heater. The worse is only two stages for backlight module operation, on or off. Event in a dark scent, brightness of backlight module is in full intensity and dark scene is made by controlling rotation angle of liquid crystal molecule. In a long term, electric power consumption is substantial. How to lower down electric power consumption becomes therefore an important issue for saving power as LCD developing.
Thus, inventors depending on their abundant experience on LCD design and producing figure out the present invention for solving mentioned problems after many cycles of consideration, produce, and modification.